Hand tools frequently need to be ground in order to provide the desired tool shape, in particular to sharpen the tools, the edges of which become dull after continued use. Unless the person grinding the tool is very experienced, grinding tools correctly is a difficult and time consuming exercise.
A number of grinding jigs have been proposed to facilitate the task of grinding hand tools, particularly woodturning tools such as gouges. In one known form of apparatus, a pivot block is provided on the floor in front of a grinder which is mounted on a bench. The tool is held by a clamp which has a leg that ends in a pivot point that is received in the pivot block. The leg is angularly adjustable relative to the clamp about a clamp pivot axis, which clamp pivot axis is located in use between the grinder and the pivot block. Such apparatus is made and sold by Glaser Engineering Co. of El Segundo, Calif., USA.
Another system is that disclosed in U.S. Pat. No. 6,393,712 (Jansson) which provides a horizontal support that is parallel to the axle of the grinding wheel and has a clamp for the tool which is pivotally mounted relative to the support.
These known forms of jig have the disadvantage that they can only be used to effectively shape or sharpen a limited variety of tools, or provide only a limited variety of ground shapes to tools. They can also be difficult to use and time consuming to set up.
Accordingly, there is a need in the art for a grinding tool jig that can accommodate a wide variety of hand tool types for sharpening or shaping, that is easy to set up and use, that is capable of being used in the field independent of the flooring or ground surface type, and that is more compact and versatile.